1. Technical Field
The present invention relates to a projector which projects images.
2. Related Art
Recently, a projector for image projection which has function of detecting installation condition of the projector or the like and automatically controlling projection condition such as focus control and trapezoidal distortion correction (automatic control function) has been proposed. For automatically controlling projection condition, a distance measuring sensor for measuring the distance to a projection surface (screen), a gravity sensor for detecting inclination of the projector in the up-down direction, and other components are provided to perform control according to detection results from the sensors, for example. Also, a predetermined test image (detection pattern) is projected and shot by an image pickup unit, and the projection condition is controlled according to the result of the shot image in another example (see JP-A-2000-241874 and JP-A-2006-60447, for example).
According to the example which controls the projection condition by using the test image as in the projector disclosed in JP-A-2006-60447, trapezoidal distortion caused by inclination not only in the up-down direction but also in the left-right direction can be corrected. Moreover, zoom control for allowing projection of images within a detected range to which images are to be projected (screen frame) can be automatically performed. Thus, usability of the projector for a user improves. According to this example, the test image is projected at the time of control. In this case, the control is automatically executed while the user is observing images, which makes the user uncomfortable. For avoiding this situation, in the structure controlling the projection condition by using the test image, the projection condition is automatically carried out only when the startup of the projector (immediately after turning on the power source) or when a definite request (operation) is given from the user.
However, some users do not know how to start the automatic control function, or do not even know that the projector has the automatic control function. When these users change the installation condition of the projector after startup, they manually control the projection condition or observe images without appropriate control. In this case, the automatic control function is not effectively utilized.